There is provided a battery state detection chip, i.e. bq 2092, within the battery pack of a portable computer system. This chip records various states of the battery, including battery voltage, temperature, charge/discharge current, capacity, and version, etc. In general, the unit of the capacity of a battery is denoted as milli-ampere/hour, i.e. MAH. It is known that, before a new battery is used, it is required to perform an initialization operation to the values of the state within the chip. The detection chip provides accurate readings during life time of the battery only when this initialization operation is accurately done.
It is well known a DCR counter is provided in the detection chip of the battery. Each time the battery experiences a discharge operation from a full charge capacity condition, this DCR counter starts to count. In addition, the detection chip of the battery also includes a full-charge-capacity (FCC) register for storing the maximum capacity value of the battery which may be obtained from DCR counter.
The calibration apparatus of the present invention together with a charge/discharge procedure is aimed to accomplish the initialization operation mentioned above.